Educate about /foo when ?!.foo (#759)

* React to message commands (!close, .close, ?close)

* matching
* advice content follows next

* Added actual advice

* javadoc, got rid of the massive Pattern.compile(".*") duplication

* unit tests

* Improved regex

* Test was unstable on CI/CD

* dot after smiley looks odd

application/src/main/java/org/togetherjava/tjbot/features/Features.java

@@ -4,10 +4,7 @@
 
 import org.togetherjava.tjbot.config.Config;
 import org.togetherjava.tjbot.db.Database;
-import org.togetherjava.tjbot.features.basic.PingCommand;
-import org.togetherjava.tjbot.features.basic.RoleSelectCommand;
-import org.togetherjava.tjbot.features.basic.SuggestionsUpDownVoter;
-import org.togetherjava.tjbot.features.basic.VcActivityCommand;
+import org.togetherjava.tjbot.features.basic.*;
 import org.togetherjava.tjbot.features.bookmarks.*;
 import org.togetherjava.tjbot.features.code.CodeMessageAutoDetection;
 import org.togetherjava.tjbot.features.code.CodeMessageHandler;
@@ -104,6 +101,7 @@ public static Collection<Feature> createFeatures(JDA jda, Database database, Con
         features.add(codeMessageHandler);
         features.add(new CodeMessageAutoDetection(config, codeMessageHandler));
         features.add(new CodeMessageManualDetection(codeMessageHandler));
+        features.add(new SlashCommandEducator());
 
         // Event receivers
         features.add(new RejoinModerationRoleListener(actionsStore, config));

application/src/main/java/org/togetherjava/tjbot/features/MessageReceiverAdapter.java

@@ -18,6 +18,13 @@ public abstract class MessageReceiverAdapter implements MessageReceiver {
 
     private final Pattern channelNamePattern;
 
+    /**
+     * Creates an instance of a message receiver, listening to messages of all channels.
+     */
+    protected MessageReceiverAdapter() {
+        this(Pattern.compile(".*"));
+    }
+
     /**
      * Creates an instance of a message receiver with the given pattern.
      *

application/src/main/java/org/togetherjava/tjbot/features/basic/SlashCommandEducator.java

@@ -0,0 +1,71 @@
+package org.togetherjava.tjbot.features.basic;
+
+import net.dv8tion.jda.api.EmbedBuilder;
+import net.dv8tion.jda.api.entities.Message;
+import net.dv8tion.jda.api.entities.MessageEmbed;
+import net.dv8tion.jda.api.events.message.MessageReceivedEvent;
+import net.dv8tion.jda.api.requests.restaction.MessageCreateAction;
+import net.dv8tion.jda.api.utils.FileUpload;
+
+import org.togetherjava.tjbot.features.MessageReceiverAdapter;
+import org.togetherjava.tjbot.features.help.HelpSystemHelper;
+
+import java.io.InputStream;
+import java.util.function.Predicate;
+import java.util.regex.Pattern;
+
+/**
+ * Listens to messages that are likely supposed to be message commands, such as {@code !foo} and
+ * then educates the user about using slash commands, such as {@code /foo} instead.
+ */
+public final class SlashCommandEducator extends MessageReceiverAdapter {
+    private static final String SLASH_COMMAND_POPUP_ADVICE_PATH = "slashCommandPopupAdvice.png";
+    private static final Predicate<String> IS_MESSAGE_COMMAND = Pattern.compile("""
+            [.!?] #Start of message command
+            [a-zA-Z]{2,15} #Name of message command, e.g. 'close'
+            .* #Rest of the message
+            """, Pattern.COMMENTS).asMatchPredicate();
+
+    @Override
+    public void onMessageReceived(MessageReceivedEvent event) {
+        if (event.getAuthor().isBot() || event.isWebhookMessage()) {
+            return;
+        }
+
+        String content = event.getMessage().getContentRaw();
+        if (IS_MESSAGE_COMMAND.test(content)) {
+            sendAdvice(event.getMessage());
+        }
+    }
+
+    private void sendAdvice(Message message) {
+        String content =
+                """
+                        Looks like you attempted to use a command? Please note that we only use **slash-commands** on this server 🙂
+
+                        Try starting your message with a forward-slash `/` and Discord should open a popup showing you all available commands.
+                        A command might then look like `/foo` 👍""";
+
+        createReply(message, content, SLASH_COMMAND_POPUP_ADVICE_PATH).queue();
+    }
+
+    private static MessageCreateAction createReply(Message messageToReplyTo, String content,
+            String imagePath) {
+        boolean useImage = true;
+        InputStream imageData = HelpSystemHelper.class.getResourceAsStream("/" + imagePath);
+        if (imageData == null) {
+            useImage = false;
+        }
+
+        MessageEmbed embed = new EmbedBuilder().setDescription(content)
+            .setImage(useImage ? "attachment://" + imagePath : null)
+            .build();
+
+        MessageCreateAction action = messageToReplyTo.replyEmbeds(embed);
+        if (useImage) {
+            action = action.addFiles(FileUpload.fromData(imageData, imagePath));
+        }
+
+        return action;
+    }
+}

application/src/main/java/org/togetherjava/tjbot/features/code/CodeMessageAutoDetection.java

@@ -34,8 +34,6 @@ public final class CodeMessageAutoDetection extends MessageReceiverAdapter {
      * @param codeMessageHandler to register detected code messages at for further handling
      */
     public CodeMessageAutoDetection(Config config, CodeMessageHandler codeMessageHandler) {
-        super(Pattern.compile(".*"));
-
         this.codeMessageHandler = codeMessageHandler;
 
         isHelpForumName =

application/src/main/java/org/togetherjava/tjbot/features/code/CodeMessageHandler.java

@@ -29,7 +29,6 @@
 import java.awt.Color;
 import java.util.*;
 import java.util.function.Function;
-import java.util.regex.Pattern;
 import java.util.stream.Collectors;
 
 /**
@@ -66,8 +65,6 @@ public final class CodeMessageHandler extends MessageReceiverAdapter implements
      * Creates a new instance.
      */
     public CodeMessageHandler() {
-        super(Pattern.compile(".*"));
-
         componentIdInteractor = new ComponentIdInteractor(getInteractionType(), getName());
 
         List<CodeAction> codeActions = List.of(new FormatCodeCommand());

application/src/main/java/org/togetherjava/tjbot/features/filesharing/FileSharingMessageListener.java

@@ -73,8 +73,6 @@ public class FileSharingMessageListener extends MessageReceiverAdapter implement
      * @see org.togetherjava.tjbot.features.Features
      */
     public FileSharingMessageListener(Config config) {
-        super(Pattern.compile(".*"));
-
         gistApiKey = config.getGistApiKey();
         isHelpForumName =
                 Pattern.compile(config.getHelpSystem().getHelpForumPattern()).asMatchPredicate();

application/src/main/java/org/togetherjava/tjbot/features/moderation/attachment/BlacklistedAttachmentListener.java

@@ -15,11 +15,10 @@
 import org.togetherjava.tjbot.features.moderation.modmail.ModMailCommand;
 import org.togetherjava.tjbot.features.utils.MessageUtils;
 
-import java.awt.*;
+import java.awt.Color;
 import java.util.List;
 import java.util.Locale;
 import java.util.function.UnaryOperator;
-import java.util.regex.Pattern;
 
 /**
  * Reacts to blacklisted attachments being posted, upon which they are deleted.
@@ -35,7 +34,6 @@ public final class BlacklistedAttachmentListener extends MessageReceiverAdapter
      * @param modAuditLogWriter to inform the mods about the suspicious attachment
      */
     public BlacklistedAttachmentListener(Config config, ModAuditLogWriter modAuditLogWriter) {
-        super(Pattern.compile(".*"));
         this.modAuditLogWriter = modAuditLogWriter;
         blacklistedFileExtensions = config.getBlacklistedFileExtensions();
     }

application/src/main/java/org/togetherjava/tjbot/features/moderation/scam/ScamBlocker.java

@@ -74,8 +74,6 @@ public final class ScamBlocker extends MessageReceiverAdapter implements UserInt
      */
     public ScamBlocker(ModerationActionsStore actionsStore, ScamHistoryStore scamHistoryStore,
             Config config) {
-        super(Pattern.compile(".*"));
-
         this.actionsStore = actionsStore;
         this.scamHistoryStore = scamHistoryStore;
         this.config = config;

application/src/main/java/org/togetherjava/tjbot/features/tophelper/TopHelpersMessageListener.java

@@ -38,8 +38,6 @@ public final class TopHelpersMessageListener extends MessageReceiverAdapter {
      * @param config the config to use for this
      */
     public TopHelpersMessageListener(Database database, Config config) {
-        super(Pattern.compile(".*"));
-
         this.database = database;
 
         isHelpForumName =

application/src/test/java/org/togetherjava/tjbot/features/basic/SlashCommandEducatorTest.java

@@ -0,0 +1,70 @@
+package org.togetherjava.tjbot.features.basic;
+
+import net.dv8tion.jda.api.entities.MessageEmbed;
+import net.dv8tion.jda.api.entities.channel.ChannelType;
+import net.dv8tion.jda.api.events.message.MessageReceivedEvent;
+import net.dv8tion.jda.api.utils.messages.MessageCreateBuilder;
+import net.dv8tion.jda.api.utils.messages.MessageCreateData;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
+
+import org.togetherjava.tjbot.features.MessageReceiver;
+import org.togetherjava.tjbot.jda.JdaTester;
+
+import java.util.List;
+import java.util.stream.Stream;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.*;
+
+final class SlashCommandEducatorTest {
+    private JdaTester jdaTester;
+    private MessageReceiver messageReceiver;
+
+    @BeforeEach
+    void setUp() {
+        jdaTester = new JdaTester();
+        messageReceiver = new SlashCommandEducator();
+    }
+
+    private MessageReceivedEvent sendMessage(String content) {
+        MessageCreateData message = new MessageCreateBuilder().setContent(content).build();
+        MessageReceivedEvent event =
+                jdaTester.createMessageReceiveEvent(message, List.of(), ChannelType.TEXT);
+
+        messageReceiver.onMessageReceived(event);
+
+        return event;
+    }
+
+    @ParameterizedTest
+    @MethodSource("provideMessageCommands")
+    void sendsAdviceOnMessageCommand(String message) {
+        // GIVEN a message containing a message command
+        // WHEN the message is sent
+        MessageReceivedEvent event = sendMessage(message);
+
+        // THEN the system replies to it with an advice
+        verify(event.getMessage(), times(1)).replyEmbeds(any(MessageEmbed.class));
+    }
+
+    @ParameterizedTest
+    @MethodSource("provideOtherMessages")
+    void ignoresOtherMessages(String message) {
+        // GIVEN a message that is not a message command
+        // WHEN the message is sent
+        MessageReceivedEvent event = sendMessage(message);
+
+        // THEN the system ignores the message and does not reply to it
+        verify(event.getMessage(), never()).replyEmbeds(any(MessageEmbed.class));
+    }
+
+    private static Stream<String> provideMessageCommands() {
+        return Stream.of("!foo", ".foo", "?foo", ".test", "!whatever", "!this is a test");
+    }
+
+    private static Stream<String> provideOtherMessages() {
+        return Stream.of("  a  ", "foo", "#foo", "/foo", "!!!", "?!?!?", "?", ".,-", "!f", "! foo");
+    }
+}

application/src/test/java/org/togetherjava/tjbot/features/reminder/RemindRoutineTest.java

@@ -184,6 +184,6 @@ void reminderIsNotSendIfNotPending() {
     private static void assertSimilar(Instant expected, Instant actual) {
         // NOTE For some reason, the instant ends up in the database slightly wrong already (about
         // half a second), seems to be an issue with jOOQ
-        assertEquals(expected.toEpochMilli(), actual.toEpochMilli(), TimeUnit.SECONDS.toMillis(1));
+        assertEquals(expected.toEpochMilli(), actual.toEpochMilli(), TimeUnit.SECONDS.toMillis(2));
     }
 }

application/src/test/java/org/togetherjava/tjbot/jda/JdaTester.java

@@ -216,6 +216,8 @@ public JdaTester() {
         doNothing().when(messageCreateAction).queue();
         when(messageCreateAction.setContent(any())).thenReturn(messageCreateAction);
         when(messageCreateAction.addContent(any())).thenReturn(messageCreateAction);
+        when(messageCreateAction.addFiles(any(FileUpload.class))).thenReturn(messageCreateAction);
+        when(messageCreateAction.addFiles(anyCollection())).thenReturn(messageCreateAction);
 
         CacheRestAction<PrivateChannel> privateChannelAction =
                 createSucceededActionMock(privateChannel, CacheRestAction.class);